Merge pull request #832 from StNekroman/master

fix

Author: eirslett

frontend-plugin-core/src/main/java/com/github/eirslett/maven/plugins/frontend/lib/ProcessExecutor.java

@@ -31,6 +31,8 @@ public ProcessExecutionException(Throwable cause) {
 }
 
 final class ProcessExecutor {
+    private final static String PATH_ENV_VAR = "PATH";
+
     private final Map<String, String> environment;
     private CommandLine commandLine;
     private final Executor executor;
@@ -96,33 +98,38 @@ private CommandLine createCommandLine(List<String> command) {
         return commmandLine;
     }
 
-    private Map<String, String> createEnvironment(List<String> paths, Platform platform, Map<String, String> additionalEnvironment) {
+    private Map<String, String> createEnvironment(final List<String> paths, final Platform platform, final Map<String, String> additionalEnvironment) {
         final Map<String, String> environment = new HashMap<>(System.getenv());
-        String pathVarName = "PATH";
-        String pathVarValue = environment.get(pathVarName);
+
+        if (additionalEnvironment != null) {
+            environment.putAll(additionalEnvironment);
+        }
+
         if (platform.isWindows()) {
-            for (Map.Entry<String, String> entry : environment.entrySet()) {
-                if ("PATH".equalsIgnoreCase(entry.getKey())) {
-                    pathVarName = entry.getKey();
-                    pathVarValue = entry.getValue();
+            for (final Map.Entry<String, String> entry : environment.entrySet()) {
+                final String pathName = entry.getKey();
+                if (PATH_ENV_VAR.equalsIgnoreCase(pathName)) {
+                    final String pathValue = entry.getValue();
+                    environment.put(pathName, extendPathVariable(pathValue, paths));
                 }
             }
+        } else {
+            final String pathValue = environment.get(PATH_ENV_VAR);
+            environment.put(PATH_ENV_VAR, extendPathVariable(pathValue, paths));
         }
 
-        StringBuilder pathBuilder = new StringBuilder();
-        if (pathVarValue != null) {
-            pathBuilder.append(pathVarValue).append(File.pathSeparator);
-        }
-        for (String path : paths) {
-            pathBuilder.insert(0, File.pathSeparator).insert(0, path);
-        }
-        environment.put(pathVarName, pathBuilder.toString());
+        return environment;
+    }
 
-        if (additionalEnvironment != null) {
-            environment.putAll(additionalEnvironment);
+    private String extendPathVariable(final String existingValue, final List<String> paths) {
+        final StringBuilder pathBuilder = new StringBuilder();
+        for (final String path : paths) {
+            pathBuilder.append(path).append(File.pathSeparator);
         }
-
-        return environment;
+        if (existingValue != null) {
+            pathBuilder.append(existingValue).append(File.pathSeparator);
+        }
+        return pathBuilder.toString();
     }
 
     private Executor createExecutor(File workingDirectory, long timeoutInSeconds) {